According to Android Police, a number of users recently received prompts from Duo asking them if they'd like to merge their call history with their handset's call log in the default Phone application.

The feature isn't actually working yet

It doesn't look like the feature is working yet though, so it's unclear whether it functions in a similar way to Apple's integration, allowing users to return calls via the call list.

However, seeing as Google recently armed Duo with the facility to place regular calls, it certainly looks like that's the direction it's headed in. After all, the option is useless if you can't click on it.